Automotive vehicle



April 18, 1939. DURHAM 2,154,497

AUTOMOTI VE VEHICLE Filed March 11, 1937 2 Sheets-Sheet} April 18, 1939.

Hv N. DURHAM AUTOMOTIVE VEHICLE 2 Sheets-Sheet 2 v a WENT-ER wwm I Patented Apr. 18, 1939 UNITED STATES AUTOMOTIVE VEHICLE Hobart N. Durham, Munsey Park, N. Y., to Differential Wheel Corporation, a corporation of Delaware Application March 11, 1937, Serial No. 130,236 10 Claims. (Cl. 188-18) The present invention relates to heavy duty automotive vehicles and more particularly to novel and useful improvements in the braking 7 mechanism for the dual road wheels forming part of the running gear of said vehicles.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom or may be learned by practice withthe invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described;

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings:

Figure 1 is a central vertical section showing the present illustrative embodiment of the invention;

Figure 2 is a fragmentary sectional view taken on'the line 2-2 of Figure 1; and

Figure. 3 is a detailed, fragmentary sectional view'pf a modified form of the invention! The present invention has for its object the provision of a novel and improved dual wheel structure for automotive vehicles, and more particula'rly to a novel dual wheel structure in which the wheels are independently rotatable and are provided with means for braking both of the vehicle wheels. A- further object of the invention -is the provision of a novel dual wheel structure having independently rotatable wheels in which the movement of one of the dual wheels with the brake applied causes the application of the brake 4n to the other wheel.

' In=the illustrative embodiment of the present invention, two dual wheels are mounted side-byside'in coaxial relation on a single axle and are adapted to be ro independently or are capais hie of relative rotation with respect to each other, and means are provided for limiting or preventv ing' such relative movement or independent rotation as the brake is applied to one wheel so that thefvehicleis brought to a stop by both a) wheeisjerrnng their retarding eifect on the velucle. A's embodied, thermal means are provided for actuating a clutch member on one wheel to render it fast or relatively immovable with respect to the other wheel, and these thermal 55 means are preferably actuated by the application of the brake to the inner wheel, the brake application resulting in sufficient heat to actuate the brake forthe outer wheel. As embodied, the force for the outer wheel braking is generated by the heating of a thermally expansible fluid and the brake or clutch member between the wheels is actuated by this fluid pressure.

It will be understood the foregoing general description and the following detailed description as well are exemplary and explanatory of the in- 10 vention but are not restrictive thereof.-

Referring now in detail to the illustrative embodiment ofthe present invention as shown by the accompanying drawings, there is provided an axle having a spindle ID on which are carried the i5 tapered roller bearings Ii and i2 for the inner wheel l3 and the tapered roller bearing ll for the outer wheel Ila plain thrust bearing it being provided between the wheels I! and it to take the axial thrust between the wheels. A nut I1 serves to retain the bearing and wheel assembly on the spindle in, a hub cap ll prevents'the entry of dirt into the bearings, while a grease retaining ring l9 prevents the escape of grease onto the brake mechanism. Rims 20 and tires 2| are mounted on the wheels in any desired and conventional manner. I

The inner wheel is provided with conventional brake mechanism comprising the backing plate 22, fixed to the axle and held fast thereon, the so brake shoes 23, the operating mechanism 24 therefor and the anchor 25, while the brake drum 26 is fast to the inner face of the wheel I8, and may be provided with radiating fins 21 for the quicker radiation of the heat generated during the stoppage of the vehicle.

. Means are provided for securely locking the wheels l3 and I! against relative rotation, there by preventing their independent rotation, so that when the brake is applied to the inner wheel, the outer wheel is also retarded. For this purpose there is provided a friction clutch between the two wheels, one of the clutch members being fastened to the inner wheelwhile the other-clutch member is fastened to the outer wheel ll. As as shown. there is provided adrum 3., similar to a brake drum, securely fastened to the inner face of the outer wheel IE. and within this drum are mounted shoes 32, similar to conventional shoes, normally spaced from the drum and held so slightly out of contact therewith. Shoes 32'are provided with a facing 33- of friction material, and are pivotaily anchored bymeans of the link 34 to an anchor post 35 projecting outwardly from the inner wheel I3; At their upper ends,

2 2,154,497 shoes 32 are joined together by means of the pisvention and without sacrificing its chief advanton rods 36 projecting from a cylinder 31 within tages. g I

which are the hydraulic pistons 38 of the hy- What I claim is:

draulic actuating means, while the shoes are normally held together, free of the drum 30, by means of the tension springs 39. Cylinder 31 is fixedly mounted to the inner wheel l3 by means of the projection 40, and thereby the shoe structure is carried'a'nd rotated by the inner wheel l3. The clutch between the two wheels is adapted to be thermally and hydraulically actuated from the braking of the inner wheel, and for this purpose there is provided a small liquid reservoir in thermal contact with the brake drum 26 of the inner wheel. and this reservoir is connected with the hydraulic cylinder 31 by means of a duct 46 which may be formed in the wheel member l3. Reservoir 45 is preferably formed as a small cavity on the exterior of the brake drum 26 in close contact therewith, and is also preferably provided-with radiating fins 41 by which the heat is quickly dissipated so that the clutching of the two wheels together is not long continued after release of the inner wheel brake.

In the operation of the described embodiment, 'during the normal travel of the vehicle, the two wheels are free to rotate independently 'of each other and in turning a corner, the wheel nearest. the center of the curve about which the vehicle is turning travels the shortest distance. Duringthis normal operation, the brake shoes 23 are out of contact with the brake drum '26, and the clutch shoes 32 are out of contact with the clutch drum When theoperator wishes to stop the vehicle, the actuator 24 is operated to apply the shoes 23 against the brake drum 26, retarding rotation of the inner wheel and heating the brake drum 26. This heating of the brake drum 28 causes the fluid in reservoir 45 to expand and the re- 7 suiting increased pressure is transmitted through duct 46 to the hydraulic cylinder-31, moving pistons 38 apart and thereby forcing the clutch shoes 32 into contact with the clutch .drum 3!. The pressure is quickly built up suillciently so that the shoes 32 are pressed against drum 30 with sufiicient pressure to lock the two wheels immovably togethen. Thereby the braking eflort applied to the inner wheel is transmitted through the clutch to the outer wheel l5 so as to retard itsrotation and assist in stopping the vehicle.

As the inner wheel brake is released, the heat is dissipated from the brake drum through the radiating fins 41 and the liquid contracts, allowing springs 39 'to retract the clutch shoes into non-contacting position, and once again permitting the independent rotation of the wheels.

Figure 3 illustrates a modified embodiment of the invention in which means are provided for relieving excessive liquid pressure of the braking fluid. As embodied, there is a resiliently expansible chamber 50 of relatively small volume atwithout departing from tached to the brake drum 26 and in communication with the liquid reservoir, so that excessive heating ofthe brake drum 26 limited pressure between the clutch shoes 32 and the drum 30. In other respects, the construction and operation of this embodiment may be the same as that previously described.

The invention" in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims the principles of the incan cause only a 1. In a dual wheel assembly for automotive vehicles, the combination of a pair of. independently rotatable wheels mounted side by side, a clutch having relatively rotatable parts carried by the two wheels and hydraulic motor means for actuating the clutch to clutch the two wheels together and braking means associated with one of the wheels.

2. In a dual wheel assembly for automotive vehicles, the combination of a pair of independently rotatable wheels mounted side-by-side, a clutch having relatively rotatable parts carried by the two wheels, and thermally actuated means for engaging the clutch to prevent relative rota-v tion of the wheels.

3. In a dual wheel hicles, the combination of a pair of independently rotatable wheels mounted side-by-side, a clutch having relatively rotatable parts carried by the two wheels and thermally actuated hydraulic means for engaging the clutch to prevent relative rotation of the wheels.

4. In a dual wheel assembly for automotive vehicles, the combination of a pair of independently rotatable wheels mounted slde-by-side, a clutch having relatively rotatable parts carried by the two wheels, a brake operating on one of the wheels, hydraulic motor means for engaging the dlutch to prevent relative rotation of the wheels and means for operating the hydraulic motor means by operation oithe brake.

5. In a dual wheel'assembly for automotive vehicles, the combination of a pair of independently rotatable .wheels mounted side-by-side, a

"wheels, and means for increasing the pressure in the hydraulic motor means by the application of the brake. v

7. In a dual wheel'assembly for automotive vehicles, thecombination of a pair of independ ently rotatable wheels mounted side-by-side, a clutch having relatively rotatable parts carried by the two wheels, a brake operating on one of the wheels, hydraulic motor means for engaging the clutch to prevent relative rotation of the wheels, said hydraulic motor means including a thermally expansible liquid, and means for heating and expanding the liquid by the application oi the brake. J

8. In a dual wheel assembly for automotive vehicles, the combination of a pair of independ: ently rotatablev wheels mounted side-by-side, a

- clutch having relatively rotatable parts carried assembly for automotive vewheels, a brake operating on one of clutch having relatively rotatable parts carried by the two wheels, and positioned between the two ently rotatable wheels mounted side-by-side, a clutch having relatively rotatable parts carried by the two wheels, and positioned between the two wheels, a hydraulic actuator for the clutch,

and fluid connections carried by one of the wheels 6 for said actuator.

HOBART N. DURHAM. 

